Mechanical pointers for instrument clusters and automotive displays typically include mechanical gears or belts as a means for controlling a motion or rotation of the pointer. The gears and belts limit design options and often produce an undesirable level of audible noise.
For example, U.S. Pat. No. 7,434,536 discloses an analog display instrument including an indicator disc having teeth formed on a peripheral edge and a stepper motor adapted to engage the teeth of the indicator disc to cause the indicator disc to rotate.
Certain rotary display elements include a piezoelectric element configured to cause a pointer/indicator to rotate. Specifically, when the piezoelectric element is electrically energized, a shape of the piezoelectric element is extended or contracted. The change in shape of the piezoelectric element is relied upon to control a particular motion of the pointer/indicator.
For example, U.S. Pat. Appl. Pub. No. 2004/0124743 discloses an actuator having a piezoelectric element. Specifically, the piezoelectric element is electrically driven by a signal having a particular waveform, which causes the piezoelectric element to expand slowly and at a pre-determined point, contract quickly. In this way, the relatively slow expansion is used to push a reciprocal drive pad and cause a rotational motion of an optical stage in a first direction. Conversely, the relatively swift contraction of the piezoelectric element causes the mechanical interface between the drive pad and the optical stage to “slip” so that the drive pad can return to an initial position without causing the optical stage to rotate in a direction opposite the first direction.
There remains a need for cost effective and robust apparatus, systems, and methods for driving a dynamic mechanical pointer over a display in automotive instrument applications.
It would be desirable to develop a display system, wherein the system provides a means for selectively controlling a motion of a mechanical pointer in various directions, while maximizing a viewable area of a display associated with the pointer.